Apparatus, methods and compositions for placing additive fluids into a refrigerant circuit

ABSTRACT

A supply canister is partially filled with a refrigerant circuit additive fluid which is partially evacuated, said refrigerant circuit additive fluid is comprised of a combination of a binding azeotrope of methanol and cyclohexanone with a drying agent, a metal sealant and a rubber rejuvinating compound in a single container.  
     Additive fluids from the canister may be placed into the refrigerant circuit of an air conditioning system by (1) connecting the canister to the circuit after it has been emptied and vacuum pressure created therein, (2) connecting the canister to the refrigerant circuit suction line during system operation, or (3) connecting the canister to the suction line with the system off, to thereby force refrigerant from the circuit into the canister, and then starting the system to cause the vacuum pressure in the suction line to draw the contents of the canister into the refrigerant circuit.

[0001] This application is a continuation-in-part application of Ser.No. 09/802,178 filed on Mar. 8, 2001, still pending.

FIELD OF THE INVENTION

[0002] The present invention relates to methods of dehydrating,passivating, sealing of refrigeration systems and a method fordelivering combination of a binding azeotrope of methanol andcyclohexanone, a drying agent, a moisture activated metal treatment andrubber rejuvinating compound into a single container.

[0003] The present invention generally relates to the maintenance of airconditioning or refrigeration systems and, in a preferred embodimentthereof, more particularly relates to apparatus and methods for placingan additive fluid in to the refrigerant circuit of an air conditioningsystem.

[0004] In the typical air conditioning or refrigeration system it isoften necessary to place an additive fluid (normally a liquid) into therefrigerant circuit portion of the system to maintain the performance ofthe system at a satisfactory level. Examples of additive fluids placedin refrigerant circuits include compressor oil, stop-leak liquid, acidneutralizers, drying agents, and ultraviolet colored leak-finder liquid.

[0005] Additive fluids of these and other types are conventionallyplaced in refrigerant circuits by one of four methods—namely, (1) therefrigerant circuits by one of four methods (2) the additive fluid isplaced in a container along with pressurized refrigerant and is expelledwith the pressurized refrigerant into the circuit; (3) the additivefluid is placed in an in-line storage device, and pressurizedrefrigerant is flowed through the storage device to force the additivefluid into the circuit along with the pressurized refrigerant; or (4)the additive fluid is injected into the circuit using a mechanicalpiston to force the fluid into the circuit.

[0006] These conventional techniques carry with them certain knownproblems, limitations and disadvantages. For example, to simply open therefrigerant circuit and pour the additive in can undesirably causerelease of refrigerant to the atmosphere, and can also undesirablyintroduce contaminating air into the circuit. Packaging an additivefluid in a container with pressurized refrigerant to be forciblyinjected into the circuit is also undesirable due the expense of addingrefrigerant to the container as a propellant, the safety concernsinherent in a pressurized container structure, and the need to match therefrigerant propellant with the type of refrigerant within the circuit.Placing the additive fluid in an in-line device requires that therefrigerant forced through the device match the refrigerant in thecircuit to avoid contamination of the circuit. Injecting additive fluidinto a refrigerant circuit using a mechanical piston device tends to bea somewhat cumbersome task requiring specialized packaging and/orequipment.

[0007] Recently, severe restrictions by the U.S. Government has beenplaced on use of chlorofluorocarbons (CFCs) due to environmentalproblems which are as a result of the destruction of stratosphericozone. In addition, CFCs have been labeled as environmentally unsafe inmany countries worldwide. As a result, proposed alternative substanceswhich can be substituted for CFCs in various applications have been andare being developed. Among them are several new proposedhydrofluorocarbons (HFCs). A substitution which is being used isHFC-R134a and related compounds. These materials are being sold as asubstitutes for CFC as a refrigerant liquid for CFC as refrigerationfluids. These replacement materials, while not ozone-depleting continueto contribute in part to the greenhouse effect. Their use and escapeinto the atmosphere is the subject of the EPA's Significant NewAlternatives Programs, which limits the use of fluroinated compounds asalternatives for ozone-depleting chemicals.

[0008] The HFC replacement fluids are generally not as efficient as CFCsand require new types of additives including fluids, sealants, metal andrubber sealants as well as dehydrates and others. In addition, redesignof compressive-evaporative refrigeration and other systems using theHFCs has been necessary. The newer working fluid refrigerants exhibitdifferent soluabilities than CFCs, and are not mixable with well knownlubricants in CFC systems as well as other additives. For example, in amodem system using these compounds in cooperation with known lubricantscauses hydrolysis of the lubricating esters in a chemical reversionprocess. Further, other chemical additives in the new environmentalpartially safe system cause additional metal and rubber leakage which,again, can bring on additional problems for the EPA and the environment.

[0009] Leaks allow refrigerants and other working fluids to escape intothe atmosphere, contaminating the environment and decreasing theefficiency and cooling capacity of the unit. If large amounts of coolingworking fluids such as refrigerants escape, the system may overheat andthe service life of the unit will thereby be shortened. Further, theunit may suffer mechanical failure from the loss of the working fluid.In general, leaks in heating and cooling systems also decrease the heattransfer efficiency of these systems.

[0010] Water in all types of compressive-evaporative systems decreasesthe system efficiency as a result of water's high heat of vaporizationand high heat capacity. The high heat of fusion of water decreases theefficiency of a compressive-evaporative system by giving off heat inevaporation cycles as the water freezes. The resulting ice crystals canalso block orifices in expansion valves and cause such systems tomalfunction.

[0011] A need continues to exist in the art for a method for sealingleaks in refrigeration, air conditioning, heating and ventilation andrelated systems and for the complete dehydration of the systems. Moreimportantly, there is a need that exist in the prior art for theaddition in a one-step application of a drying agent, a moistureactivated metal treatment and a rubber rejuvinating compound in a singlecontainer in combination with a binding azeotrope.

[0012] As can readily be seen from the foregoing, a need exists forimproved apparatus, methods for placing additive fluids and saidadditive fluids into a refrigerant circuit. It is to this need that thepresent invention is directed.

SUMMARY OF THE INVENTION

[0013] In carrying out principles of the present invention, inaccordance with a preferred embodiment thereof, a specially designedvessel or canister is provided for use in placing an additive fluid,representatively an additive liquid, into the refrigerant circuit of anair conditioning or refrigeration system, representatively an automotiveair conditioning system. In a preferred embodiment thereof, the vesselhas an interior communicatable with a suction line portion of therefrigerant circuit, the vessel interior being partially filled with anadditive liquid, being partially evacuated to a vacuum pressure lessthan that of the suction line portion during operation of the airconditioning system, and being substantially devoid of refrigerant.

[0014] According to a first method of utilizing the partially evacuatedvessel, the interior of the vessel is initially communicated with theinterior of the suction line portion during operation of the airconditioning system, representatively using a refrigerant recharge hoseassembly, whereupon the greater vacuum pressure in the suction lineportion of the refrigerant circuit draws the additive liquid into thesuction line portion.

[0015] According to a second method of utilizing the partially evacuatedvessel, the refrigerant circuit is emptied and a vacuum pressure iscreated therein which is greater than the vacuum pressure within thevessel. The vessel is then communicated with the interior of therefrigerant circuit, representatively using a refrigerant recharge hoseassembly, whereupon the greater vacuum pressure within the emptiedrefrigerant circuit draws the additive fluid into the refrigerantcircuit.

[0016] Accordingly to a third method of utilizing the partiallyevacuated vessel, the interior of the vessel is initially communicatedwith the interior of the suction line portion, representatively using arefrigerant recharge hose assembly, while the air conditioning system isturned off and a positive pressure exists in the interior of the suctionline portion. The positive pressure within the suction line portionforces refrigerant therefrom into the vessel, thereby positivelypressurizing its interior. Next, the air conditioning system is turnedon to create a negative pressure within the suction line portion,thereby drawing the refrigerant and additive liquid from the positivelypressurized canister interior into the suction line portion.

[0017] The provision and use of the specially designed partiallyevacuated vessel provides a variety of advantages over conventionalpressurized canisters containing refrigerant and liquid additive. Forexample, since there is no refrigerant in the vessel, the same additiveliquid-containing vessel can be used with a wide variety of airconditioning or refrigeration systems that utilize different type ofrefrigerants—the vessel does not have to be “matched” to a particulartype of refrigerant in a circuit in order to avoid contamination thereofby a different type of refrigerant within the vessel.

[0018] Moreover, since refrigerant is not packaged within the vessel,the material cost of the partially filled vessel is substantiallyreduced. Additionally, since there is no refrigerant disposed within theas-manufactured vessel it cannot leak refrigerant into the atmosphere,and the lack of pressurized refrigerant within the as-manufacturedvessel renders it safer to ship and store.

[0019] The present invention also includes a method for dehydratingrefrigeration systems as well as a method for sealing metal and rubberparts in a refrigerant system. This is accomplished by the invention byusing a azeotrope like material with at least 2 to 3 or more additiveswhich are needed by modern air conditioning systems. The invention alsoincludes a method of dehydrating and passivating the refrigerant systemshaving a fluid enclosure. The method comprises adding a single additivemix maintained in a binding azeotrope like material which allows thetreatment of a refrigerant system for many purposes including metal andrubber sealing, dehydration and the like. In a one step application, forexample, in R134a systems. The composition containing multiple additivesand an azeotrope type mixture is allowed to react with interior surfacesof the enclosure of the refrigerant system to passivate, coat thesurfaces as well as dehydrate the whole refrigerant system thuscompleting a one application treatment for the refrigerant system. Anazeotrope or azeotrope mixture of refrigerant additives for sealing bothrubber and metal surfaces within a refrigeration system which alsodehydrates the system simultaneously because of the dehydrator which ispresent and is also included in the common container. The compositionsinclude various elements which combine and operate within the bindingazeotrope to deliver from a one container or one mix the desired amountof each sealing, dehydrating and treatment of refrigerant systems.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIG. 1 is a schematic diagram of a representative air conditioningsystem into the refrigerant circuit portion of which an additive fluidis being placed using a specially designed, partially evacuated additivefluid canister embodying principles of the present invention.

[0021]FIG. 2 schematically illustrates the canister after its additivefluid has been placed into the refrigerant circuit, with FIGS. 1 and 2together illustrating first and second methods of placing an additivefluid into the refrigerant circuit; and

[0022]FIGS. 3 and 4 are schematic diagrams similar to those in FIGS. 1and 2 and together illustrate a third method of placing an additivefluid and into a refrigerant circuit using the partially evacuatedadditive fluid canister.

DETAILED DESCRIPTION OF THE INVENTION

[0023] Schematically depicted in FIGS. 1 and 2 are first and secondmethods of placing an additive fluid 10 in the refrigerant circuit 12 ofan air conditioning or refrigeration system which is representatively anautomotive air conditioning system 14. The additive fluid 10 isrepresentatively an additive liquid such as, for example, compressoroil, a stop-leak liquid, an ultraviolet colored leak-finder liquid, anacid neutralizer, or a drying agent. The air conditioning system 14 isrepresentatively of the direct expansion type and comprises the usualcompressor 16, condenser 18, expansion valve 20 and evaporator 22connected as shown in the refrigerant circuit 12. Compressor 16 isdisposed between suction and liquid line portions 12 a, 12 b of thecircuit 12, with suction line portion 12 a having a low side pressuretap or service fitting 24 installed therein, and liquid line portion 12b having a high side pressure tap or service fitting 26 installedtherein. During operation of the system 14, refrigerant is flowedthrough the circuit 12 in the direction indicated by the circuit flowarrows in FIG. 1.

[0024] According to a key feature of the present invention, a speciallydesigned vessel or canister 28 (see FIG. 1) is partially filled with theadditive liquid 10 and is partially evacuated to a vacuum pressuresuitable for the air conditioning system with which the canister 28 isto be used (representatively in the range of from about 12″ to about 15″Hg vacuum for an automotive air conditioning system refrigerant circuit)which is (1) less than the vacuum pressure within the refrigerantcircuit suction line portion 12 a (typically in the range of from about20″ to about 30″ Hg vacuum for an automotive air conditioning systemrefrigerant circuit) during operation of the air conditioning systemrefrigerant circuit) during operation of the air conditioning system 14with refrigerant operatively flowing through the circuit 12, and (2)less than the positive pressure within the suction line portion 12 a(for example, about 78.4 psig when the ambient temperature is 75 degreesF.) when the air conditioning system 14 is not operating, andrefrigerant is not being flowed through the circuit 12.

[0025] As schematically depicted in FIG. 1, the partially evacuatedinterior 30 of the canister 28, as originally fabricated, contains onlythe additive liquid 10 and is devoid of refrigerant. The canister 28thus differs in two primary regards from conventional additive injectioncanisters—namely, (1) it does not contain refrigerant, and (2) itsinterior is at a substantial negative pressure as opposed to beinghighly pressurized. Canister 28 is of a suitable metal material and hasa hollow cylindrical body 32 with a lower end 34 and an upper end 36having an externally threaded tubular projection 38 thereon, theprojection 38 having a closed upper end 40.

[0026] Representatively, the refrigerant circuit 12 schematicallydepicted in FIG. 1 is filled with R134a refrigerant, with the suctionline service fitting 24 being of a different configuration than that ofthe liquid line service fitting 26. However, the principles of thepresent invention are not limited in any manner to an R134a refrigerantcircuit. To place the additive liquid 10 into the refrigerant circuit 12using a first method of the present invention, the interior 30 of thecanister 28 (see FIG. 1) is communicated with the interior of therefrigerant circuit 12, using a conventional R134a refrigerant rechargehose assembly 42 which is illustrated in phantom for purposes ofillustrative clarity.

[0027] Recharge hose assembly 42 includes a quick disconnect fitting 44(or another type of connection fitting such as a threaded fitting)interconnected by a length of refrigerant charging hose 46 to aninternally threaded tapping/dispensing valve 48 having a rotatablehandle 50 useable to axially drive a piercing stem portion 52 of thevalve 48. To ready the canister 28 for use in placing the additiveliquid 10 into the refrigerant circuit 12, the tapping/dispensing valve48 (with its piercing stem 52 in an upwardly retracted position) isthreaded onto the tubular projection 38 of the canister 28, and thequick disconnect fitting 44 is connected to the suction line serviceport 24.

[0028] With the air conditioning system 14 running, and refrigerantbeing operatively flowed through the suction line portion 12 a at avacuum pressure greater than that in the partially evacuated canisterinterior 30, the tapping/dispensing valve handle 50 is operated topierce the upper end 40 of the canister projection 38 and place canisterinterior 30 in communication with the interior of the suction lineportion 12 a. As indicated by the arrows 54 in FIG. 1, the higher vacuumpressure in the suction line portion 12 a draws the additive liquid 10from the partially evacuated canister interior 30 into the suction lineportion 12 a, thereby emptying the canister 30 of its additive liquidcontent as shown in FIG. 2.

[0029] This higher vacuum pressure emptying of the canister 28 may befacilitated by inverting the 28 and holding it higher than the suctionline service fitting 24. After the additive liquid 10 is placed into therefrigerant circuit in this manner, the refrigerant recharge hoseassembly 42 is disconnected from the service fitting 24 and the canister28 and the now emptied canister 28 discarded.

[0030] With continued reference to FIGS. 1 and 2, a second method ofutilizing the specially designated, partially evacuated canister 28 toplace its additive liquid 10 into the refrigerant circuit 12 is tocommunicate the interior 30 of the canister 28 with the interior of therefrigerant circuit (e.g., at its suction line portion 12 a), using thehose assembly 42, while the refrigerant circuit 12 has been emptied forrepair and has a service vacuum pressure within the interior 30 of thecanister 28. The service vacuum pressure within the refrigerant circuit12 pulls the additive liquid 10 from the canister interior 30 into therefrigerant circuit 12 as indicated by the arrows 54 in FIG. 1.

[0031] A third method of utilizing the specially designed, partiallyevacuated canister 28 to place its additive liquid 10 into therefrigerant circuit 12 is schematically illustrated in FIGS. 3 and 4 towhich reference is now made. Utilizing this second method, with the airconditioning system 14 initially being turned off, so that refrigerantis not being flowed through the circuit 12 and a positive pressure ispresent in the interior of the suction line portion 12 a, the partiallyevacuated canister 28 is interconnected via the hose assembly 42 to thesuction line service fitting 24, with the tapping/dispensing valve 48being in its closed position, as previously described. The valve handle50 is then rotated to axially drive the stem 52, pierce the canisterprojection 38, and initially communicate the partially evacuatedcanister interior 30 with the positively pressurized refrigerant withinthe suction line portion 12 a.

[0032] As depicted in FIG. 3, this causes positively pressurizedrefrigerant 56 from within the interior off the suction line portion 12a to be forcibly flowed into the partially evacuated canister interior30 via the hose 46, as indicated by the arrows 58 in FIG. 3, to becomein effect a carrier for the additive liquid 10. Next, the airconditioning system 14 is turned on to create an operative flow ofrefrigerant 56 through the circuit 12 and generate in the suction lineportion 12 a a vacuum pressure. The positive pressure previously createdin the interior 30 of the canister 28 by the forcible injection ofrefrigerant 56 thereinto causes the liquid additive and refrigerant10,56 within the canister interior 30 to be flowed into the suction lineportion 12 a, via the hose 46, as indicated by the arrows 60 in FIG. 4,thereby substantially emptying the canister 28 of its refrigerant andadditive contents. This transfer of refrigerant and additive to thecircuit 12 may be facilitated by inverting the canister 28 andpositioning it at a higher level than that of the suction line servicefitting 24. After such transfer is completed, the refrigerant rechargehose assembly 42 is disconnected from the canister 28 and the servicefitting 24, and the emptied canister 28 discarded.

[0033] The provision and use of the specially designed partiallyevacuated canister 28 provides a variety of advantages over conventionalpressurized canisters containing refrigerant and liquid additive. Forexample, since there is no refrigerant in the canister, the samecanister can be used with a wide variety of air conditioning orrefrigeration systems that utilize different types of refrigerants—thecanister does not have to be “matched” to a particular type ofrefrigerant in a circuit in order to avoid contamination thereof by adifferent type of refrigerant within the canister.

[0034] Moreover, since refrigerant is not packaged within the canister,the material cost of the partially filled canister is substantiallyreduced. Additionally, since there is no refrigerant disposed within theas-manufactured canister it cannot leak refrigerant into the atmosphere,and the lack of pressurized refrigerant within the as-manufacturedcanister renders it safer to ship and store.

[0035] The pressurization can be a refrigerant gas which carries alongwith it the various additives as discussed above. The dehydrating andsealing compositions preferably each include at least one compound andgenerally include two or more compounds of each requirement fordehydration, metal sealing and rubber sealing. The object of the presentinvention is to provide an improved air conditioning system treatmentcomposition, in which the improvement provides for the combination of adrying agent, a moisture-activated metal treatment and a rubberrejuvenating compound into a single container, unlike conventional airconditioning systems where multiple containers are used. The improvedair conditioning system treatment composition comprises of a bindingazeotrope like material, the binding azeotrope is preferred to bemethanol and cyclohexanone combined with a drying agent, a moistureactivated metal treatment and a rubber rejuvinating material. Thecombination of a binding azeotrope of methanol and cyclohexanone with adrying agent, and a moisture activated metal treatment and rubberrejuvinating compound into a single container is not known.

[0036] For purposes of this invention, a mixture of two or morecomponents is azeotropic if it vaporizes with no change in thecomposition of the vapor from the liquid. Specifically, azeotropicmixtures include both mixtures that boil without changing composition,and mixtures that evaporate at a temperature below the boiling pointwithout changing composition. Accordingly, an azeotropic mixture mayinclude mixtures of two components or more over a range of proportionsfor each specific proportion of the components is azeotropic at acertain temperature but not necessarily at other temperatures. Azeotropeand azeotrope like compositions vaporize with no change in theircomposition. If the applied pressure is above the vapor pressure of theazeotrope, the azeotrope evaporates without change. If the appliedpressure is below the vapor pressure of the azeotrope, the azeotropeboils or distills without change. The vapor pressure of low boilingazeotropes is higher and the boiling point is lower than that of theindividual components. In fact, the azeotropic composition has thelowest boiling point of any composition of its components. Thus, theazeotrope can be obtained by distillation of a mixture whose compositioninitially departs from that of the azeotrope. Azeotropes can exist insystems containing two liquids (A and B) as binary azeotropes, threeliquids (A, B and C) as ternary azeotropes, and four liquids (A, B, C,and D) as quarternary azeotropes.

[0037] For purposes of this invention, other alcohols can be used incombination as an azeotrope. The term alcohols represents a broad classof hydroxyl-containing organic compounds. For example, monohydricalcohols of about one to three carbon atoms can be used or variousdihydric, trihydric and polyhydric alcohols for forming azeotropessuitable for the present inventive mix. Furthermore, these alcohols whendehydrated act as a water scavenger. Even though the alcohols are usedin the azeotropes or azeotrope like mixtures. These dehydrated alcoholscan be a part of the azeotrope or can operate independently as a waterscavenger. Those dehydrated alcohols which do form azeotropes orazeotrope like mixtures can also scavenge water.

[0038] In one preferred method and composition, the sealing compositionswhich are preferably added to the dehydrating compositions and thepassivating compositions for a one time injection into the refrigerantsystem function with and are compatible with each other. The sealingcompositions circulate within the fluid enclosure within the system asdoes the passivating and dehydrating compositions. If the system has aleak, the sealing composition exits through the leak and hydrolyticallyreacts with moisture in the atmosphere to form a polymeric seal on theexternal surface of the system.

[0039] Preferred fluorocarbon-based working fluids useful in conjunctionwith the compositions of the additive fluids of the present inventioninclude those having a numerical fluorocarbon code designated by theAmerican Society of Refrigerating Engineers (ASRE). Preferred ASRE codesinclude 11, 12, 12B1, 13, 13B1, 14, 21, 22, 32, 42, 115, 124, 125,134,R134a, 143a, 152a, 161, 218, and 227.

[0040] Preferably, the working fluids chosen are compatible with thecompositions used in the methods and fluid mixes and the compositionsare chosen to be soluble in the working fluid, the lubricant or both theworking fluid and the lubricant. In one embodiment, the composition canbe chosen so that one compound within the composition is preferentiallysoluble in the working fluid and the other compound in the compositionis preferentially soluble in the lubricant. It should be understood,based on this disclosure, that other working fluids meeting theabove-criteria may be used with the present compositions withoutdeparting from the spirit of the invention.

[0041] The invention will now be described in more detail with respectto the following specific, non limiting example:

EXAMPLE

[0042] The passivation effect, the dehydrating compositions as well asthe sealants of the present invention in combination with the azeotropesand carrier material is demonstrated by comparing the surface energiesof untreated substrates through the surface energies of substratestraded with the various additives. Various additives all contain silanesand organic silanes for cross-linking metal bonding and rubber sealants.High surface energies are indicated by low contact angles due to polarattractions. The removal of the polar nature of the surface byincorporation of silicon groups repels highly polar water moleculesresulting in high contact angles (which can approach 90 degrees)indicating lower surface energy.

[0043] A typical vacuum pack contains from about one and a half ouncesof refrigerant additives to greater quantities and size of the packdepending on the need. The one and a half ounces of additive iscomprised of ¾ ounce of metal sealants having the composition of 60% byvolume of vinyltrimethoxysilane, 30% by volume ofn-beta(aminoethyl)gamma-aminopropyltrymethoxysilane; and 10% by volumeof methyltrimethoxysilane, a water scavenger. The other additiveconstituting ¾ of an ounce of a 1½ ounce vacuum pack load is comprisedof 50% by volume methanol and 3% by volume of (1) a mix comprising 35%by volume cyclohexanone and 65% by volume methylene chloride; and 47%PAG. These two additive mixtures and azeotropes are carried by R134acarrier which constitutes another ½ ounce load for the vacuum packedload, bringing the total to 3 ounces. These additives specificallymentioned are joined together in an azeotropic mixture which allows theuser to load his vacuum pack or other delivery packaging systems withvarious amounts, however in this case a total of 3 ounces of additivesand R134a carrier, which constitutes the refrigerant in most cases. Inreview, the methyltryoxysilane is a water scavenger and the vinyltrimethylsilane is a metal bonding material which then-beta-(aminoethyl)-gamma-aminopropyltrymethoxysilane is for crosslinking. While the methanol and cyclohexanone do provide the azeotropewith the cyclohexanone acting as a penetrant and methyl chloride as asoftener. The final component is PAG which is polyalkylene glycols(PAGs) and polyol esters which constitute the new lubricants suitablefor R134a refrigerants and the like. The water in a system using theselubricants does cause hydrolysis of the lubricating esters in a chemicalreversion process. The foregoing detailed description is to be clearlyunderstood as being given by way of illustration and example only, thespirit and scope of the present invention being limited solely by theappended claims.

What is claimed is:
 1. An additive fluid for refrigerant circuits areselected from at least two compounds of the group consisting of abinding azeotrope, a drying agent, a moisture-activated metal sealantand a rubber rejuvinating compound; the at least two compounds arecontained in one fluid additive.
 2. An additive fluid according to claim1 wherein the azeotrope is comprised of methanol and cyclohexanone. 3.An additive fluid according to claim 1 wherein the metal sealants arecomprised of organo-silane compounds.
 4. An additive fluid according toclaim 1 wherein the azeotrope is comprised of about 98% by volume ofmethanol and about 2% by volume cyclohexanone.
 5. An additive fluidaccording to claim 1 wherein the drying agent is comprised of adehydrated alcohol having one to three carbon atoms per molecule.
 6. Thedrying agent according to claim 1 wherein dehydrated dihydric, trihydricand polyhydric alcohols scavenge for water and are capable of formingazeotrope or azeotrope-like mixtures.
 7. An additive fluid forrefrigerant circuits comprising compositions consisting of an azeotrope,drying agent, a moisture-activated metal sealant, and a rubberrejuvinating compound, selected from the group consisting of; (1) metalsealants comprising 10% by volume of a water scavenger, 60% by volume ofa metal bonding compound and 30% by volume of a cross-linking compoundall of which are organo-silane compounds; (2) an azeotrope comprisingabout 50% by volume methanol and about 1% by volume cyclohexanone, mixedwith about 2% by volume methylene chloride, a softener and about 47% byvolume of PAG oil; (3) a drying agent comprised of a dehydrated alcoholhaving one to three carbon atoms per molecule; (4) about an equal amountof all the other components of R134a carrier; and (5) the compositionsare contained in the same fluid.
 8. A method of placing an additivefluid into a refrigerant circuit, said method comprising the steps of:providing a vessel having a partially evacuated interior partiallyfilled with an additive fluid, said additive fluid comprising acombination of a binding azeotrope, a drying agent, a moisture-activatedmetal sealant and a rubber rejuvinating compound; and communicating therefrigerant circuit with said partially evacuated interior of saidvessel.
 9. The method of claim 8 wherein said providing step isperformed using a vessel partially filled with an additive fluid,comprising a combination of a binding azeotrope, a drying agent, amoisture-activated metal sealant and a rubber rejuvinating compound. 10.The method of claim 8 wherein said providing step is performed using avessel having an interior vacuum pressure in the range of from about 12″Hg to about 15″ Hg.
 11. The method of claim 8 wherein said communicatingstep is performed by operatively interconnecting a refrigerant rechargehose assembly between said vessel and said refrigerant circuit.
 12. Themethod of claim 8 wherein: said refrigerant circuit includes a suctionline portion which, during operative flow of refrigerant therethrough,has a vacuum pressure greater than the vacuum pressure within saidvessel, and said communicating step includes the step of communicatingsaid partially evacuated interior of said vessel with the interior ofsaid suction line portion, during operative flow of refrigeranttherethrough, in a manner flowing said compound comprising an azeotrope,a drying agent, a moisture-activated metal sealant and a rubberrejuvinating compound into said suction line portion from a commoncontainer.
 13. A method of placing an additive fluid comprising acombination of a binding azeotrope, a drying agent, a moisture-activatedmetal sealant and a rubber rejuvinating compound, into a refrigerantcircuit, said method comprising the steps of: providing a vessel havinga partially evacuated interior partially filled with the additive fluidand being substantially devoid of refrigerant, and communicating theinterior of said refrigerant with said partially evacuated interior ofsaid vessel.
 14. The method according to claim 13 wherein: saidrefrigerant circuit has a suction line portion which, during operativeflow of refrigerant flow therethrough, has a vacuum pressure greaterthan the vacuum pressure within said vessel, and said communicating stepis performed by communicating the interior of said suction line portionwith said partially evacuated interior of said vessel during operativeflow of refrigerant through said suction line portion.
 15. The methodaccording to claim 13 wherein: said refrigerant circuit has a suctionline portion which, during operative flow of refrigerant therethrough,has a vacuum pressure greater than the vacuum pressure within saidvessel, said suction line portion, in the absence of an operative flowof refrigerant flow therethrough, has a positive pressure, saidcommunicating step is performed by communicating said partiallyevacuated interior of said vessel with the interior of said suction lineportion, during an absence of operative refrigerant flow therethrough,to thereby force refrigerant from said refrigerant circuit into saidvessel, and said method further comprises the step, performed after saidcommunicating step, of creating an operative flow of refrigerant throughsaid suction line portion to thereby draw refrigerant and additiveliquid into said refrigerant circuit from within said vessel.